1. Field of the Invention
The present invention relates to a distance measuring apparatus, and more particularly, to a distance measuring apparatus which can measure the distance to an object using the time interval between the time when a light source emits light to an object and the time when light reflected by the object is received.
2. Description of the Related Art
In general, a distance measuring apparatus using light, such as a laser beam, calculates the distance from the distance measuring apparatus to an object whose distance is to be measured (hereinafter, referred to as ‘object to be measured’) by using the difference between the time when a light source emits reference light for distance measurement and the time when an optical sensor detects reflected light, which is the reference light reflected by the object to be measured. A pulse laser or a separate counter may be used to determine the time difference.
The related art distance measuring apparatus using light is installed such that the direction of reference light emitted from the light source has an angular difference of about 90° from the direction of reflected light which is made incident onto the optical sensor, serving to detect the reflected light, after being reflected by the object to be measured.
For example, the related art distance measuring apparatus includes a light source, a first mirror, a second mirror and an optical sensor. Here, the first mirror changes the path of reference light emitted from the light source by an angle of 90°. The second mirror changes the path of the reference light, sent from the first mirror, toward an object to be measured, and changes the path of reflected light, the reference light reflected by the object to be measured, to the direction in which the reference light is made incident. The optical sensor receives the reflected light, the path of which has been changed by the second mirror. The first mirror may be installed between the optical sensor and the second mirror.